I've just reciently tried them.
In the short distance I shoot (about 20 yards), there's not a whole lot of difference...other than they are a lot more solid. By that I mean, they don't ripple and make noise while in the air. Yes...you can hear a long fletching out of a fast CB in the quiet of a long hallway in my house.
Anyway...this tells me that they are flying straighter and faster. Much less wind resistance.

Mike